There is a place that appears like a mirage. Disappearing and reappearing over and over again. In this place, people have been disappearing. Seria, a knight of the kingdom, has come to this place to investigate the rumors of villagers suddenly disappearing. However, that place was a labyrinth where starved demons run rampant... Within the dungeon, there are many monsters and traps. A woman wearing a white tunic, adventurers, a suspicious man wearing a hood, the disappearing villagers... Are they friends or enemies? Will Seria be able to solve the mystery of this place and escape...?